This invention relates generally to hydraulic winches, and more particularly to a control system that is used to control the free fall rotation of the drum of a spud winch.
It is known to anchor a barge in a river by releasing an elongated spud or pile that drops from the barge and sinks to the bottom, penetrating the river bed. The spud is suspended from the barge by a cable so that the barge is anchored by the spud to the river bottom, and the cable is spooled on the drum of a hydraulic winch provided on the barge so that the spud can be pulled from the river bottom and raised to release the barge for navigation.
In order to release the spud to anchor the barge, it is conventional to provide the hydraulic winch with a clutch assembly connected between the hydraulic motor of the winch and the drum such that the drum can be disengaged from the motor to rotate freely. By providing this feature in the winch, the spud can be released to free fall to the bottom of the body of water in which the barge is to be anchored, gathering velocity during the free fall to penetrate the river bed by an amount sufficient to anchor the barge in place.
After the spud penetrates the river bottom during an anchoring operation, the velocity of the spud drops off quickly. However, because the free spooling drum continues to rotate under its own momentum, slack is created in the cable, causing tangling or knotting thereof. This effect is referred to as bird nesting, and can damage or ruin the cable. As such, there is a need in the art for a winch having a system for controlling operation of the clutch so that the spud can be released for free fall during anchoring, and rotation of the drum can be subsequently braked to prevent bird nesting of the cable.